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3 years ago

Which best describes a row of elements in the periodic table?

Physics

1 answer:

marissa [1.9K]3 years ago

5 0

Answer:

well i know that the horizontal rows are called periods and the vertical ones are called groups

Explanation:

I don't really know what this question is exactly asking

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What do electrons in the same shell have in common? AThey have the same amount of energy incorrect answer BThey are all positive

Keith_Richards [23]

Answer:

They have the same amount of energy

Explanation:

Electrons are said to be the subatomic particles that move around the nucleus of an atom. These electrons are negatively charged particles that are seen to be quite smaller than the nucleus of an atom.

The electron shells of these atoms are usually being filled from the inside out with the low-energy shells closer to the nucleus being filled before they can go into the much higher-energy shells that are a bit out

8 0

3 years ago

Tell me that all answers plz

ki77a [65]

Answer:

a. Value of MA is always lesser than VR because mechanical advantage decreases due to the friction and weight of moving parts of the machine.

b.Efficiency of lever is never 100 or more because it will always lose some tiny (sometimes immeasurable) percentage of power due to the lever bending.

c.Because it helps to apply more torque.

d.Because the upright snip has the blades rotated 90° from the handles.

e.because some of the input work is used to overcome friction.

f.because the load arm is always longer than effort arm.

g.because the effort arm is always longer than load arm of these Lever.

h. because if the effort distance is greater than load distance there will be magnification of force and the metals could easily cut.

i. because the wheelbarrow's wheel and axle help the wheelbarrow to move without friction thus making it easier to push or pull.

8 0

3 years ago

Read 2 more answers

Suppose a clay model of a koala bear has a mass of 0.200 kg and slides on ice at a speed of 0.750 m/s. It runs into another clay

kaheart [24]

Answer:

0.278 m/s

Explanation:

We can answer the problem by using the law of conservation of momentum. In fact, the total momentum before the collision must be equal to the total momentum after the collision.

So we can write:

$mu=(m+M)v$

where

m = 0.200 kg is the mass of the koala bear

u = 0.750 m/s is the initial velocity of the koala bear

M = 0.350 kg is the mass of the other clay model

v is their final combined velocity

Solving the equation for v, we get

$v=\frac{mu}{m+M}=\frac{(0.200)(0.750)}{0.200+0.350}=0.278 m/s$

8 0

4 years ago

A projectile is launched at an angle of 45° from the horizontal and lands 21 s later at the same height from which it was launch

irinina [24]

Answer:

a) initial speed of projectile = 145.5 m/s

b) Maximum altitude = 540 m

c) Range = 2160.6 m

d) r = (1440î + 480j) m

Explanation:

The distance at any time for the projectile is given by the relation - r² = x² + y²

where x = horizontal distance covered covered by the projectile and y = vertical distance coveredby the projectile

Let the initial velocity be u = ?

angle of projection be θ with respect to the horizontal = 45°

u = (uₓî + uᵧj) m/s

T = total time of flight = 21 s

t = any time during the flight of the projectile

a) Total time of flight = 2 uᵧ/g = (2u sin θ)/g

21 = (2u sin 45°)/9.8

u = 145.5 m/s

b) maximum altitude of the projectile = H

H = (u² sin² θ)/2g

H = (145.5² sin² 45°)/(2 × 9.8)

H = 540 m

c) According to projectile motion the maximum horizontal displacement is given by

x = R = uₓT = u cos(θ) T (since uₓ = u cos θ)

R = (145.5 cos 45°) × 21 = 2160.6 m

d) At 14 s,

x = uₓt = u cos(θ) t (since uₓ = u cos θ)

x = (145.5 cos 45°) × 14 = 1440.1 m

y = uᵧ t - 0.5gt² = [u sin(θ)] t - 0.5gt² = (145.5 sin 45°) × 14 - 0.5(9.8)(14) = 480 m

r = (1440î + 480j) m

6 0

3 years ago

two 200 pound lead balls are separated by a distance 1m. both balls have the same positive charge q. what charge will produce an

Anna [14]

Answer:

The charge is $q = 3.14 *10^{-4} \ C$

Explanation:

From the question we are told that

The mass of each ball is $m = 200 \ lb = \frac{200}{2.205} = 90.70 \ kg$

The distance of separation is $d = 1 \ m$

Generally the weight of the each ball is mathematically represented as

$W = m * g$

where g is the acceleration due to gravity with a value $g = 9.8 m/s^2$

substituting values

$W = 90.70 * 9.8$

$W = 889 \ N$

Generally the electrostatic force between this balls is mathematically represented as

$F_e = \frac{k * q_1* q_2 }{d^2}$

given that the the charges are equal we have

$q_1= q_2 = q$

$F_e = \frac{k * q^2 }{d^2}$

Now from the question we are told to find the charge when the weight of one ball is equal to the electrostatic force

So we have

$889 = \frac{9*10^9 * q^2}{1^2}$

=> $q = 3.14 *10^{-4} \ C$

5 0

3 years ago